Let’s speak about the psychological aspect of a street collision. You should differentiate two items. You must realize, whether your fight is a result of a usual domestic conflict, or you are attacked by a robber, killer or bandit. Your actions will flow depending on these circumstances.
If it is an everyday domestic conflict that happens in the street (someone pushed you or your leg, disturbed the queue order etc.), you should not use your fighting knowledge and skills to put your opponent out of action.

As a rule, all these conflicts occur because of trifles, and you need to behave normally in this case, let’s say naturally. When this conflict happens, no one wants to fight actually, but just gets rid of the negative energy that was accumulated.
Those who express harshly their negative reaction are not dangerous at all in most cases. He will threaten you, make expressive gestures, grab you with iron fingers but nothing more will happen. This is nothing but the pose which does not contain real threat at all.

However, there are exceptions in this case too. You must define at once who is dangerous and who is not.
I would like to precise one thing. Though laws and principles of a hand-to-hand fighting are the same, a sports battle in a gym differs greatly from that one happened in the street. If you are calm when fight in a sports gym and don’t worry about fatal injury, you will be extremely nervous when come across your real enemy in the street. You won’t fight according to rule (as you do in the sports gym), you need to act most quickly and cruelly sometimes for your effective self defense.
The psychological aspect plays a very important role in the street scuffle. You must prevent your enemy’s attack or take the lead over him. Therefore, I advise you on no account not to start fighting if you see you can avoid it.
If you cannot do that and you know you will be attacked inevitably, you should act quickly, harshly and be the first with attack actions.

Lots of things depend on who starts the battle first. This is the main distinction of a street fight. When you train in the sports gym, it is not important at all who will attack first. Both fighters are ready to attack and defense.
It is not the same thing in the street fight. Opponents rarely stand at the certain stances (as in the sport gym) and are situated in close distance quite often. In other words, they are in the hitting zone of each other. Hence, a person who starts his attack first has a huge advantage. Attack here means just the most harsh and strong action and not the expressive gestures at usual domestic conflict.
I always feel awkward when I am forced to come into such conflict.

When I see a person standing in front of myself and offending me, I feel ashamed for this conflict that occurred. This person cannot be dangerous for me, he is completely defenseless.
I know that I can put him out of action in a moment, but my consciousness does not let me do that. As we see, such clashes that happen in shops, public transport, streets etc are not the fight itself, but just an everyday conflict.
Real fight happens when your enemy or enemies are certain in their superiority over you. For example, it may be numerical advantage, force advantage or armament advantage.
So, I strongly recommend to you: try to avoid street fight at any cost. If you see you are about to be attacked, you need to act most quickly and harshly. You must always remember that if your enemy is eager to fight with you, he is sure in his superiority. If he is alone and is not too strong or high, but still wants to fight, it means most likely that he is either armed with the weapon or instructed of some martial art.